Chelonia of the Bouldnor Formation (Eocene/Oligocene), Isle of Wight: Taphonomy and pathologies

Abstract

This study aims to establish that chelonian carapace and plastron from the Bouldnor Formation display the presence of pathologies, whilst considering the impacts of taphonomic grade and depositional environment. Describing healed injuries and evidence of disease features in detail when assessing the cause of such pathologies, causes can include disease, parasitic behaviour, predation, or post-mortem scavenging. Evaluating the impact and effects of taphonomic processes on specimens can help when diagnosing the cause of any described abnormalities. Anatomical abnormalities in Chelonians from the Bouldnor Formation are rarely documented and are also poorly preserved thus making it difficult to determine the cause for observed pathologies. Using samples collected during this study, along with museum specimens and the application of micro-CT, it is possible to identify and diagnose endogenous from exogenous impacts that have given rise to chelonian pathologies. The evidence collated in this study suggests that specimens from the Bouldnor Formation display multiple pathologic features from several different causes. Specimens show evidence of both pre-and post-mortem processes that have left distinctive marks that can be identified. This study illustrates that there is value in analysing partial specimens that other studies might have overlooked, this permits the identification of key structures that can be compared between both extinct and extant chelonians to better constrain their genesis. The evidence presented in this study indicates a wealth of information is present in fossils of extinct chelonian that give insight into the scars of injury and disease (pathologies) and suggest this would make a productive area for future research.

Date of Award	31 Dec 2023
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Phillip Manning (Supervisor) & Victoria Egerton (Supervisor)